% plot best solution
function plot_best_solution(best_solution, city_locations)
len = length(best_solution);
best_solution_location = zeros(len, size(city_locations, 2));

for i = 1:len
    best_solution_location(i,:) = city_locations(best_solution(i),:);
end
plot(best_solution_location(:,1), best_solution_location(:,2), 'bo-');
end